CVE-2026-44660

UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Prior to 5.12.1, when ujson.dump() writes to a file-like object and the write operation raises an exception, the serialized JSON string object is not decremented, leaking memory. Each failed write operation leaks the full size of the serialized payload. This vulnerability is fixed in 5.12.1.
Configurations

Configuration 1 (hide)

cpe:2.3:a:ultrajson_project:ultrajson:*:*:*:*:*:python:*:*

History

02 Jun 2026, 18:00

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.5
References () https://github.com/ultrajson/ultrajson/commit/82af1d0ac01d09aa40c887b460d44b9d9f4bccd9 - () https://github.com/ultrajson/ultrajson/commit/82af1d0ac01d09aa40c887b460d44b9d9f4bccd9 - Patch
References () https://github.com/ultrajson/ultrajson/releases/tag/5.12.1 - () https://github.com/ultrajson/ultrajson/releases/tag/5.12.1 - Product, Release Notes
References () https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg - () https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg - Exploit, Mitigation, Patch, Vendor Advisory
First Time Ultrajson Project ultrajson
Ultrajson Project
CPE cpe:2.3:a:ultrajson_project:ultrajson:*:*:*:*:*:python:*:*

30 May 2026, 02:16

Type Values Removed Values Added
References () https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg - () https://github.com/ultrajson/ultrajson/security/advisories/GHSA-c38f-wx89-p2xg -

27 May 2026, 21:16

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-27 21:16

Updated : 2026-06-02 18:00


NVD link : CVE-2026-44660

Mitre link : CVE-2026-44660

CVE.ORG link : CVE-2026-44660


JSON object : View

Products Affected

ultrajson_project

  • ultrajson
CWE
CWE-401

Missing Release of Memory after Effective Lifetime